I'm sorry, but you're assuming that a yeast in a sweet mead environment is done fermenting when it hits its a hypothetical max alcohol tolerance or when ALL of the yeast has flocced out. I just don't think that's correct. First of all, alcohol tolerance (using a wine yeast, no less) is rarely what makes yeast crap out. It's almost always lack of readily available fermentables and nutrients.

I'm not assuming that at all. As I mentioned, the "tolerance" is just one of the many factors of yeast that is impossible to predict on a regular basis. It's a guideline and can't be used accurately to bottle carb. In theory, it has some merit, but in real life - you're risking bottle bombs, which is why I have said this whole time that it's not recommended.

Quote:

Originally Posted by wendelgee2

Second, honey is full of all sorts of complex sugars that the yeast is not able to ferment. Not all flavors that you perceive as sweetness are generated by compounds that yeast are able to ferment.

Say what??? Honey is super fermentable. Even moreso than malts, which is why our meads routinely end up UNDER 1.000.

If there were that much residual non-fermentable sugars, we'd see a marked difference in our hydrometer readings and would be reading FG numbers more like beers.\

Say what??? Honey is super fermentable. Even moreso than malts, which is why our meads routinely end up UNDER 1.000.

Clearly you're right.

But, sweet meads can end up at 1.015 or sometimes much higher depending on the OG. So, what is left over? It's been through 9 months or more of fermentation. Everything that can be eaten has been, right?

I'm sorry, but you're assuming that a yeast in a sweet mead environment is done fermenting when it hits its a hypothetical max alcohol tolerance or when ALL of the yeast has flocced out. I just don't think that's correct. First of all, alcohol tolerance (using a wine yeast, no less) is rarely what makes yeast crap out. It's almost always lack of readily available fermentables and nutrients. Second, honey is full of all sorts of complex sugars that the yeast is not able to ferment. Not all flavors that you perceive as sweetness are generated by compounds that yeast are able to ferment.

What jezter has stated is essentially correct.

Alcohol is typically what causes yeast to slow down and die. It disrupts a wide range of internal cellular processes as it accumulates in the cell. In a healthy fermentation with well nourished yeast, the alcohol eventually poisons them.

There are many things that can cause a fermentation to stick before the alcohol level gets to the typical tolerance level - really low pH, lack of nutrients, lack of aeration, temperature, yeast toxins, spoilage organisms and so forth. In these cases, one should be very careful before bottling and should consider stabilizing. There is an old saying in winemaking that the best way to get a stuck fermentation going again is to bottle it. Later on, chemical changes that occur can allow shifts in the pH, or breakdown of yeast can release nutrients for other yeast to use, or warming up may reactivate the yeast and you can have fermentation in the bottles. Yes, I've definitely done it, and I've reached the point where I never trust a fungus.

A fermentation that is undernourished can go on almost imperceptibly for months with no visible airlock activity and just a very slow drop in gravity over time. Brother Adam, the revered mead maker at Buckfast Abbey did not use nutrient supplements and described continued fermentation in his sack strength batches for up to 2 years. So yes, if there is still sugar around, and the yeast are below their alcohol tolerance, there is a definite risk of renewed fermentation.

By the way, 98% of the sugars in honey are fermentable (on average).

Medsen

__________________"Our results are merely the result of carefully managing the transformation of bee spit into yeast excrement."
--- Wayneb

But, sweet meads can end up at 1.015 or sometimes much higher depending on the OG. So, what is left over? It's been through 9 months or more of fermentation. Everything that can be eaten has been, right?

What's left over is mostly fermentable sugar. If the yeast have been poisoned by the alcohol, they can't eat any more. If they have been poisoned with sulfite and sorbate, they can't eat any more. If they have been pasteurized they are dead. If they have been filtered out, then they are gone.

If none of those things is the case, the the possibility of renewed fermentation should addressed.

__________________"Our results are merely the result of carefully managing the transformation of bee spit into yeast excrement."
--- Wayneb

So, to go back to my previous question, you can't just add priming sugar to a sweet mead, because either the yeast is dead drunk, or it's cleared so much that there simply isn't enough present to ferment the remaining honey sugars, much less the priming sugar.

Got it.

Thanks for the patience, folks.

btw, not to hijack this thread, but a lot of my misconceptions were based on a previous thread here where I was wondering about adding bourbon to a cider in order to raise the alcohol level and thus inhibit a portion of the fermentation, so the cider would retain some sweetness and more apple character. I was told that that absolutely wouldn't work and it would ferment out anyway. But...I'm thinking now that they were wrong.

btw, not to hijack this thread, but a lot of my misconceptions were based on a previous thread here where I was wondering about adding bourbon to a cider in order to raise the alcohol level and thus inhibit a portion of the fermentation, so the cider would retain some sweetness and more apple character. I was told that that absolutely wouldn't work and it would ferment out anyway. But...I'm thinking now that they were wrong.

There's a lot of theoretical in there. How much bourbon did you want to add? What was the (after bourbon) ABV expected to be?

And maybe, what they were trying to tell you is that 1) it wasn't going to be a SURE thing, or 2) just because you add the alcohol now doesn't mean them yeast are instantly dead - they may continue on their last legs until they're officially poisoned, or 3) Maybe they were saying the same thing that if you think upping the ABV to exactly 14% - it might not kill the yeast because some live past the expected tolerance and it's not an absolute science.

If you added bourbon to the point where you were easily over 20% ABV - one would think that you would most assuredly kill the yeast in a day or two.

This is all kinda hypothetical though.

If you're interested in trying it out, I'd recommend doing a 1g cider batch and add bourbon and see how well it works. You just have to ensure you add enough bourbon to COMPLETELY overwhelm the yeast's tolerance, which pretty much means it's well over standard cider territory.

It will work if you add enough alcohol, but I expect the taste would be rather harsh.

Another approach you can take if you want a sweet cider (non-sparkling) with more apple character is to let the yeast take it dry, then stabilize with sorbate and sulfite and backsweeten it with apple concentrate.

__________________"Our results are merely the result of carefully managing the transformation of bee spit into yeast excrement."
--- Wayneb

I'm going to repost what I posted earlier in the hopes it doesn't get drowned by another aside into fermentation behavior at higher alcohol levels:

I was buying dry ice recently and noticed that the dry ice manufacturer had included a "recipe" for homemade soda. It entailed putting some small quantity of dry ice into a bottle (PET for their case), adding flavored sugar water, and capping. Voila - sparkling fizzy drink. That got me thinking - can you sorbate a mead, bottle it with some dry ice and carbonate it that way? Has anyone tried this? You'd need a scale, of course, but seems like this could work.